Sanding machine



Sept. 23, 1930. R. A. REID 1,776,450

SANDING MACHINE Filed Feb. 19, 1927 M00000 M00000 M00000 I M00000 17649606060 U M00000 '3(0OOOCD M00000 Patented Sept. 23, 1930 PATENT OFFICE RAYMOND A. REID, or CEDAR sAr ns, Iowa SANDING MACHINE Application filed. February 19, 1927. Serial No. "169,642.

This invention relates to power-driven "apparatus for Sanding wood surfaces, the embodiment of the invention herein shown being more'especially designed for finishing 6 operations at a bench and manual movement of the machine.

The principal object of this invention 18 to provide a sanding machine with adequate means for catching the dust arising from 10 the operation of the machine, and for arresting its escape into the air of the room in which the work is performed. This is a matter of prime importance in the operation of any sander, and presents difiiculties 15 that'are not easily overcome.

The machine-herein 1 illustrated is of a special type, employing as the sanding drum the cylindrical shell which carries the'field coils of an electrical motor. This is mounted in a suitable housing, the bottom .of

after more particularly appear.

In the accompanying drawing, form ng a part of this specification, Fig. 1 is a side elevation of a sander embodying the invention. Fig. 2 is a plan'view of the same. Fig.3 is a sectional View in the plane of the line 38 of Fig. 2. Fig. 4: is a sectional View of the same, looking toward the left,

on the staggered line fh4 of Fig. 3.

. To a base 5 having a flat bottom, with anopening at 6 for a little of the periphery of the sanding roller'T, is connected, as by a hinge 8at each side, a rear housing 9. Th1s -of a shaft 11, which carries the armature of anelectric motor. The details of the sanding roll are not important to this invention further than is herein illustrated, comprising the cylindrical field-coil shell 12 above referred to, and a pair of heads 13 secured thereto, as by screws 14. Over this is drawn a cushioning ring of felt, or the like, 15, and to this is suitably'applied the sheetof abrasive 16. In operation the sanding .roll,with the field coils attached, revolves on the fixedaxis of the. armature (not shown, except as to the shaft 11).

i In front of the housing just described is mountedanother housing 17, which serves which serves as a surface guide, as will here- F is recessed at 10 to receive the flattened ends as an air outlet and dust screen. At its foot it has depending flanges l7 a fitting neatly inside the upstanding flanges 5 of the base. At the top it is made to interlock with the rear housing by means of spring clips 18. The'front and upper part of this dust-trap is pierced with holes 17 for the escape of air. Inside of this is stretched a sheet of fabric of asuitable mesh to catch the dust, but permit the air to pass through, and inside of this is a protective screen of woven wire 19, holding the fabric in place. I

The heads of the roller are provided'with' :radial fan blades 13,which'in the revolution of the roller in the direction indicated by the arrow tend to force the dust arising from the sanding of the surface below,

7 back into the rear housing and thence over the roller into the considerable space between the roller and the dust trap in front.

,Air for this current is admitted through openings 20 at each side of the housing. In

practice this current of airand dust does not pass in a direct sheet from the bottom to the top of the roller and forward, but is deflected inwardly behind the roller and takes a forwardlyand inwardly converging course, as indicated by the arrows 1n- Flg. 2. The practical effect of this is that no dust or air escapes at the sides of the machine, and the only outlet for the air inf-lowing at the sides is through the screen of the dust-trap, as above described.

One of the difficult problems to solve has been toprevent leakage of-air and dust between the joints of the housings and base,

as thrown about by the rapidly revolving roller. To prevent this, at the sides, the inner-cheeks of the dust-trap are lined with felt 21, the inner edges of the felt overlapping the rim of the roller and its felt, as

'indicated'by the curved dotted line in Fig. 8,

and as also shown in Fig. 4:. This makes a dust-tight joint between the whole forward part of the roller and thesides of the dusttrap, with but little friction between the revolving roller and the fixedparts.

In the forward part of the base a pocket 22 is formedby the side walls and vertical ribs 5 and and into this pocket falls the principal body of'dust. The raising and.

the machine.

lowering of the roller with respect to the base, to adjust it to its work, necessarily'varies the gap at 23 to some extent. The felt liners of the cheeks protect the side gaps, and to shield the front gap 24 a rectangular sheet of felt 25 ,is folded at 25 and securely clamped to the lower front edge ofthe dusttrap. This closes every avenue of escape for the dust, While allowingjair to circulate freely. The accumulating dust must of course be emptied from time to time, but in the meantime the sander does its Work with, no scattering of dust in the room. A strip of felt '26 clamped to the upper,-rear edge of the dust-trap seals'the joint at the top of At the back of the rear housing the escape of dust at the joint 27, which varies slightly by theadjustment of the housing with respect to the base, is prevented by carrying the inwardly disposed rib 28 a little higher than the bottom edge of the housing, so that the ascending current of air and dust is carried past the joint without leakage.

Having thus described .my invention, I

. claim 1. In a sand-er, a supporting base, a circumferentially closed rear housing carried by the base, a housing forming a forward dust-trap joining the rear housing and base, and'perforated for the escape of air, a forwardly disposed dust pocket formed in the base, and fibrous cheek5pieces lining the sides of the dust-trapiand contacting closely with and a dust-trap joining the rear housing and the base forward of the roller, the front of.

for a part of a roller to project therethrough,

a housing structure having a roller revolubly mounted therein provided on its ends with fansblades,said-housing having openings for admitting air to the fan-blades at its sides and openings spaced therefrom for the escape of air. 7 I I In testimony whereof I afiiX my signature;

- RAYMOND'ACREID.

the ends of the roller inits arc of movement through said trap.

2.1111 a sander, a supporting fora part of a roller to Droiect therethrough, a rear housing closed peripherally, a sanding roller revoluble therein, andv provided a with end fan-blades, anda dust-trap housing base, opened I joining the rear housing and thebase for-' and closed peripherally, a dust-trap housing wardly, pierced at the sides for admission of 1 air to the fans, and forwardly'for theescape of air, and screened against the escape of dust. e

3. In a sander, a supporting base, opened for the projection of a peripheral arcof a roller, a rear housing mountedon the base,

disposed-forwardly thereof and over the voluble in said housings and providing with base, with'side openings to admit air and" front openings to. permit its escape, and a dust-retaining screen,"asanding roller re- 12 0 end fan blades, and fibrous dust-proof linings I for the dust-trap to closethejoints between sides over-lapping and lying close to oneend the dust-trap. V c 4. In a sander, a base apertured forthe .66 it and the rear housing and base,.tliose at the of the roller in its arc ofmovernent through projection of a roller rim, a rear housing 'carried the base, aroller revoluble therein, 7 

